Explosive.



UNTTED STATES PATENT OFFICE.

GIOANNI CORNARO, OF TURIN, ITALY.

EXPLOSIVE.

No Drawing.

To all whom it may concern:

Be it known that I, GIOANNI CORNARO, a subject of the King of Italy, residing at Turin, in Italy, have invented certain new and useful Improvements in the Manufacture of Explosives, of which the following is a specification.

This invention relates to improvements in the manufacture of explosives.

I have ascertained that very much greater explosive force is obtained by using a mixture of different metals than by using the metals singly, if the mixture is an intimate one and consists of suitable proportions of two or more metals which begin to oxidize at different temperatures, and the successively formed oxygen compounds of which de velop, during their formation, increasing quantities of heat, so that the oxidation of one of them induces, by the heat developed, the more rapid and complete oxidation of the other metal or metals, of which the oxidation takes place at a higher temperature.

This process constitutes an improvement of great importance and allows of obtaining explosive forces considerably greater than those obtained by means of the most powerful nitrogen compounds. If the two metals, aluminium and zinc, are mixed with each other in suitable proportions, together with a suitable quantity of oxid or highly oxidized salt, as for example manganese dioxid, chlorates, perchlorates or nitrates, the oxidation of one of the metals develops heat by which the oxidation of the other metal is caused to take place with more completeness and with the development of a greater amount of heat and consequently of explosive force. During the first phase of the explosion the zinc is first oxidized by the oxidizing agent at the moment of igniting the explosive and the heat of formation assists and accelerates the formation of aluminium oxid Al,O,,. The heat of formation of the latter added to that of the zinc oxid raises the temperature to the temperature at which compounds are formed, which may be higher oxids of zinc and aluminium. The final result is that the metals, aluminium and zinc, are completely oxidized with such development of heat that they are in a gaseous state at the end of the explosion. It is necessary that the explosion of an explosive of this nature takes place in a projectile, mine, torpedo or the like, to prevent the expansion and cooling of the gases in course of forma- Specification of Letters Patent.

Application fi1ed April 8, 1910. Serial No. 554,119.

Patented Apr. 18, 1911.

tion. tured by the method described are formed with nitrate of potassium, explosion does not take place below a temperature of approximately 300 degrees centigrade, and is not readily produced by the action of impact or friction.

By alteringthe proportions of the metals mixed with each other, different explosive forces "or rapidities of explosion are obtained, according to the purpose for which the explosive is required. As examples 2- 21.5 per cent. of aluminium, 21.5 per cent. of zinc, and 57 per cent. of perchlorate of potassium give an explosive of high disruptive power. 20 per cent. of aluminium, 20 per cent. of zinc, and 60 per cent. of nitrate of If the metallic explosives manufacpgt z sgi um gtve a lower disruptive power.

The explosive is compounded in the same way as black powder.

At the very high temperatures of explosion the oxide and metallic anhydrids are believed to be gaseous, but immediately after the explosion and consequent expansion and cooling of the gases the latter rapidly become condensed and solidified, but remain in a state of fine division, so that they remain suspended in the atmosphere and form a thick and slowly dispersing smoke, visible at a considerable distance.

The explosives produced in the manner described therefore have the following advantages:l. High power. 2. Production of thick, slowly dispersing smoke, enabling the location of the explosion to be detected at a distance. 3. Insensitiveness to impact and friction within the gun and on impact with highly resistant bodies such as armor-plates, cement or concrete walls and the like, so that the explosives are suitable for charging projectiles and in general for all purposes for which explosive agents are required.

Certain metals are, more particularly when finely pulverized, liable to become oxidized at ordinary temperatures. To prevent this, such metals may be coated with a protective varnish of materials which are perfectly stable at ordinary temperatures, and constitute an explosive when in contact with the oxid or salt mixed with the metal. A varnish suitable for this purpose may be produced by mixing in equal proportions, soot, boiled linseed oil and oil of turpentine to form a paste. The percentage of soot, however, may be varied to give to the paste the required fluidity. This varnish is applied to the metallic powders of the explosives in the proportion of 2 to 4 per cent. in Weight. With 4- per cent. or more of such varnish the explosive will not explode in the open air, or if inclosed in a receiver of weak resistance.

WVhat I claim as my invention and desire to secure by Letters Patent of the United States is 1. An explosive comprising a mixture of aluminium and zinc in finely divided condition With a solid inorganic oxidizing agent.

2. An explosive comprising a mixture of aluminium and zinc with perchlorate of po- 1 5 gas iania 3. An explosive comprising a mixture of alummlum and zinc \v1th an alkall-metal Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

- Washington, D. 0.

salt capable of rapidly oxidizing said aluminium and zinc.

4. An explosive consisting of a mixture of aluminium and zinc in a finely divided condition, a solid inorganic oxidizing agent, and a grish coating the particles of said metals consisting? ot, lo oi oil flhiiznentine, g A oxidizing agent an oxidizable explosive constituent.

In Witness whereof I have signed this specification in the presence of two Witnesses.

GIOANNI CORNARO.

lVitnesses CARLO ToR'rA, JocELYN GOUBEYRAN. 

